You might happen to have a WordPress blog whose URLs you need to rewrite, perhaps because you've changed category to topic and you don't want to lose that sweet search engine traffic.

Here's a quick way to do it with nginx:

1. Open your site's configuration in your favorite text editor: sudo nano /etc/nginx/some.site
2. Look for the the location block, it looks similar to this:

   location / {
        try_files $uri $uri/ =404;
   }
   

3. Add the rewrite directive:

   location / {
        rewrite ^/category(.*)$ /topic$1 permanent;
        try_files $uri $uri/ =404;
   }
   

This redirects all /category requests to /topic. That's it!